if it really hot and has a lot of toppings so that it will make a big mess, then yes, but, normally, just eat it with your hands if possible. but, make sure to wash them first- well most of the time.
Another common way to eat a Pizza is to partially fold the slice. One has to take care doing this if it is hot or has a lot of toppings, since the toppings and cheese can spill over that way. In that case, get a plate and utensils, and either eat it with utensils or at least eat over a plate and use the utensils to eat or replace what falls off.
You eat it with your hands. But if you like you can eat it with a fork and knife.
Eat with fork and knife or eat little bites
Try folding the pizza slice, then try eating it..
with a knife and fork
Knife and fork
With a knife and fork.
with a knife and a fork
With your fork and knife.
twist the pasta around the fork or knife and then stick the whole thing in your mouth.
Italian people are no different than anyone else and yes, they do use a knife and fork and in some cases use a fork with a spoon to twirl their pasta around the fork so it does not splatter everywhere.
If you are out in a restaurant then you should eat chicken with a knife and fork. You can use your fork to pull the meat away from the bone or, cut pieces of the chicken with your knife and then use your fork to eat it. If in a high end restaurant you do not pick chicken up with your hands and eat it as that is not etiquette, but if you are at a family orientated restaurant this is acceptable.
Upper class people who like pizza would eat it with a knife and fork , cut it all into small bite sized pieces and chew very slowly perhaps with a glass of wine or champagne.